The present invention relates to the utilization of permanent magnets to produce helically oriented magnetic fields which are particularly useful in circularly polarized microwave/millimeter-wave devices in electronics work. The utilization of high power, broad-band radiation sources for microwave and millimeter-wave radars is particularly enhanced by the availability and inclusion of helical undulator or twister designed magnetic field generators. These effects have been achieved, prior to the time of the present invention, by means of current carrying coils of very high amperage adapted to produce a helically varying transverse magnetic fields of the magnetization desired. By the use of permanent magnet structures of particularly designed geometries in accordance with the present invention, the need for current carrying coils and the attendant weight and space problems have been obviated.
In several earlier inventions, notably U.S. Pat. No. 4,654,618, Mar. 31, 1987, and U.S. Pat. No. 4,658,228, Apr. 14, 1987, the effective utilization of rare earth permanent magnetic materials for the effective replacement of ferrite permanent magnets and/or electromagnets for the effective containment and control of electron beams without any substantial loss of field flux for applications in miniaturized magnetic devices in communications circuits and the like is taught. The '228 patent discusses the confinement of longitudinal axially symmetric magnetic fields and confining these fields with great precision to annular regions within permanent magnetic structures. The '618 patent teaches the confinement of magnetic field to very small areas in miniature devices. Both of these patents teach the basic concept of using particularly formed and especially shaped cladding magnets and the use of rare earth compound materials as effective magnetic substitutes for straight ferrites and what is more important, for electromagnetic devices.
The basic teachings concerning the methods by which rare earth materials are put into place in magnetic elements and devices and which are described with great particularity in the two aforementioned patents, are incorporated by reference as teachings in this disclosure.
With the above-described need for the production and control of helically oriented flux fields, we conceived and developed the present invention to provide for the application of permanent magnets made of the rare earth compound materials designed and arranged in certain specific ways in order to produce the desired helical or "twisted" fields without the need for large and bulky ferrite magnets and/or electromagnetic elements.
It is, therefore, a primary object of this invention to provide permanent magnet structures made of rare earth compound materials which can effectively produce magnetic fields which are helically defined and oriented to control the passage of electrons therethrough accordingly.
It is a further object of this invention to provide for the application of cladded magnet structures in this unique and advantageous way for the production of the desired helical magnetic flux fields.
A further and important object of the invention is to attain by approximation as accurately as possible the form of an ideal or idealized structure which, because of its nature, would be extremely difficult, if not impossible, to structurally produce by any presently known fabrication or assembly means.
These and other objects, features, and details of the invention will become the more readily apparent in light of the ensuing detailed description and disclosure, particularly in the light of the drawing wherein:
FIGS. 1, 2, and 3 show, successively, in perspective view, the basic magnetic structure, the ideal structure, if such could be attained in reality, and the actual structure according to the invention of a first embodiment of apparatus according to the invention;
FIGS. 3, 4, and 5 show, successively, a basic structure of a magnet, the idealized version of same if such could be attained in reality, and the actual structure of the apparatus according to the invention, all in perspective view, of a second embodiment of apparatus according to the invention; and
FIGS. 7, 8, and 9 show, successively, a basic cladded magnet structure, the idealized version of a magnet according to the invention if such could be attained in reality, and the actual apparatus according to the invention, all in perspective view.